import{ Firebase }from'@ionic-native/firebase/ngx';constructor(private firebase: Firebase){}...this.firebase.getToken().then(token =>console.log(`The token is ${token}`))// save the token server-side and use it to push notifications to this device.catch(error =>console.error('Error getting token', error));this.firebase.onNotificationOpen().subscribe(data =>console.log(`User opened a notification ${data}`));this.firebase.onTokenRefresh().subscribe((token:string)=>console.log(`Got a new token ${token}`));